Such transmissions are used in drive-trains of a wind power plant, in particular to transmit power of at least 1 MW. For this, the blades of a rotor exposed to wind drive an input shaft, which is connected in a rotationally fixed manner to a planetary carrier mounted so that it can rotate. On the planetary carrier are attached planetary bolts, on each of which a planetary gearwheel is mounted to rotate. The planetary gearwheels mesh with a rotationally fixed ring gear and/or a rotating sun gear.
The planetary gearwheels can rotate on the planetary bolts by virtue of so-termed planetary bearings. These are axially fixed on one side by the planetary carrier and on the other side by a shoulder of the planetary bolt. The distance of the shoulder from the face of the planetary carrier opposite it defines the axial play or prestressing of the planetary bearing.
To ensure a constant axial play or a constant prestressing even under load, the planetary bolts have to be fixed in the planetary carrier in such manner that even under load no displacement takes place, The planetary bolts are usually shrink-fitted into the planetary carrier. To ensure that the frictional holding force between the planetary bolts and the planetary carrier can bear loads to the extent required, the planetary carrier has to be strongly heated. For this, temperatures higher than 100 degrees are usual. That is not only expensive in energy terms, but also entails a high risk of injury for the fitter assembling the unit.
Furthermore, the connection between the planetary carrier and the planetary bolts must be of sufficient size. The material needed for this increases the costs and takes up fitting space.